What is Strabismus?
Strabismus, often called “crossed eyes,” simply means eye misalignment. Strabismus may be horizontal (inward or outward) or vertical.
Some children have a large amount of crossing from very early infancy. Onset usually occurs before six months of age with no improvement after that age. This is called congenital esotropia. Early surgery is often required to make the eyes straight and to allow the brain to learn to use both eyes together.
More commonly the eyes are straight at birth, but then begin to cross at about age two or three. This crossing is often intermittent at first and usually occurs when a child is tired or attempting to focus on things up close. An examination will often show considerable farsightedness, and glasses will sometimes help straighten the eyes and reduce the crossing. Surgery will be needed if the eyes cross despite the use of glasses.
Vertical Strabismus is when an eye may drift upward either constantly or intermittently. Glasses do not help with this form of misalignment. Patching to make the weak eye stronger may improve control of misalignment, but will not eliminate it. If the misalignment is frequent when looking straight ahead, then eye muscle surgery may be needed.
Eye misalignment can occur in adults as well as children. Many adults with eye misalignment have had this since childhood. In some instances, the misalignment was never fixed, or the eyes drifted again after being treated early in childhood. In these cases, there is seldom an underlying medical cause. However, adults with new-onset eye misalignment require prompt further evaluation. Some causes of sudden onset in adults may be trauma, diabetes, thyroid disease, or neurologic conditions.
Strabismus is a condition in which the eyes do not properly align with each other when looking at an object. One eye may turn inward (esotropia), outward (exotropia), upward (hypertropia), or downward (hypotropia). The misalignment can be constant or intermittent and may affect one or both eyes. Strabismus affects approximately four percent of children in the United States and can also occur in adults.
Strabismus can result from problems with the eye muscles, the nerves that control them, or the control center in the brain that directs eye movements. Contributing factors include family history, uncorrected refractive errors (particularly farsightedness), certain medical conditions such as cerebral palsy or Down syndrome, and in adults, causes may include stroke, trauma, diabetes, thyroid disease, or neurological conditions. In some cases, the exact cause is not known.
Intermittent eye crossing in infants younger than four months can be a normal part of visual development. However, persistent or constant misalignment beyond this age is not something children outgrow. Without treatment, strabismus can lead to amblyopia (lazy eye) and permanent vision loss in the affected eye. A pediatric ophthalmologist should evaluate any child with persistent eye misalignment.
Strabismus is diagnosed through a comprehensive eye examination that includes assessment of visual acuity in each eye, evaluation of eye alignment and movement, a refraction to check for uncorrected prescription errors, and examination of the eye’s internal structures. Specialized tests may be used to measure the angle of misalignment and determine how the eyes work together.
Treatment depends on the type and cause of strabismus and may include prescription glasses to correct underlying refractive errors, patching or atropine drops to treat associated amblyopia, prism lenses to reduce double vision in adults, and eye muscle surgery to reposition the muscles that control eye movement. Botulinum toxin injections are used in some cases. The treatment plan is individualized based on the patient’s age, type of misalignment, and vision needs.
Strabismus surgery is a common and generally safe outpatient procedure that has been performed for many decades. It involves adjusting the muscles that control eye movement to better align the eyes. Like all surgeries, there are potential risks including infection, bleeding, overcorrection or undercorrection, and rarely, vision changes. Many patients achieve significantly improved alignment, and some may require additional surgery over time to maintain results. Your surgeon will discuss specific risks and expected outcomes before the procedure.
Yes. Adults can develop strabismus due to stroke, head trauma, thyroid eye disease, diabetes, neurological conditions, or as a recurrence of childhood strabismus that was previously treated. Adult strabismus often causes double vision, which can significantly affect daily activities. Treatment options for adults include glasses with prisms, eye muscle surgery, and in some cases, botulinum toxin injections. Adults should not assume that strabismus treatment is only effective in childhood.
All of our doctors are trained to recognize strabismus. However, our doctors will often refer to one of our partners who is a sub-specialist trained to manage the more severe cases. Our sub-specialty trained doctor is Scott A. Davis, M.D.
Our modern, efficient facilities include four offices in Greenville, Simpsonville, and Easley. Each offers one-stop convenience for examinations, eyewear selection, purchase, and fittings.
